1. Field of the Invention
This invention relates to vacuum cleaners, and in particular to suction tools for use in vacuum cleaners.
2. Description of the Prior Art
In one conventional form of vacuum cleaner, a nozzle is provided at the end of a hollow tube, or wand, for applying suction to the surface to be cleaned and permitting dirt loosened from the surface to be sucked in by a stream of air drawn through the nozzle and tube to the dirt collecting receptacle of the vacuum cleaner. The conventional suction nozzle of this type is transversely elongated with the tube extending from the mid-portion thereof. Thus, in the conventional nozzle arrangement, maximum suction is applied at the midportion of the nozzle.
One of the deficiencies of the conventional nozzle is its inability to efficiently suck dirt at the opposite ends of the nozzle. This presents a vexatious problem where the unit is being utilized to clean a floor surface adjacent a wall or other upright obstruction. Thus, conventionally, resort is had to bringing the nozzle to adjacent the wall with the direction of elongation thereof parallel to the wall surface requiring substantial repeated manipulation of the vacuum cleaner to effect the desired cleaning of the floor surface adjacent the wall. Such repeated manipulation presents the further problem of potential damage to the wall surfaces as the nozzle must be brought directly up to the wall in effectively cleaning the entire floor surface edge.
A number of different suction nozzle devices have been developed in an attempt to solve this vexatious problem. Thus, as shown in U.S. Pat. No. 1,782,882 of S. H. Rippey, the nozzle is provided with means defining conduits extending to the opposite ends of the nozzle with the flow of air through the conduits being selectively blocked by a manipulatable valve and with the center portion of the nozzle remaining open at all times.
In the subsequent U.S. Pat. No. 1,895,584 of D. B. Replogle, an air cleaning tool is provided with an end closure means which is movable as a result of a downward pressure on the nozzle adjacent the side wheels to provide a controlled flow of air through the end openings. The wheels in the Replogle structure are disposed outwardly of the opposite ends of the nozzle, thereby preventing disposition of either nozzle end directly at a wall.
In U.S. Pat. No. 2,555,979 of G. E. Lofgren, a suction nozzle is shown having a valve for concentrating air flow at the end of the nozzle by varying the amount of closure of the mid-portion of the nozzle. At no time is the entire nozzle open to the tube.
In L. A. Wolf U.S. Pat. No. 3,550,183, a vacuum cleaner cleaning tool is shown having passages leading to the front corners of the nozzle. No means is provided for selectively controlling the relative air flow between the different portions of the nozzle inlet opening.